This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are interested in improving the treatment of port-wine stains and understanding the changes that take place in skin structure and function resulting from the application of therapeutic laser energy. Ultimately, we aim to develop a tailored approach to therapeutic laser application and in particular, to the clinical management of individual Port Wine Stain (PWS) patients receiving laser therapy. To this end we must develop objective means to better match laser treatment parameters to lesion characteristics. We propose a series of investigations that will employ modulated imaging and diffuse optical spectroscopy (DOS) to elucidate a quantitative framework for understanding skin composition and response to damage in order to better frame laser therapies.